This invention relates to drains and other utility inlet or outlet type fixtures installed in concrete slabs or floors, and, more particularly, to a system for installing such fixtures using a concrete coring adaptor around which the slab is poured. As used herein, the term fixture is generally intended to include inlet or outlet type utility fixtures such as plumbing drains or drain fixtures, cleanouts, or cleanout fixtures as well as inlets or outlets for electrical conduit or other utility applications.
Drains or drain fixtures are installed in concrete slabs, such as concrete floors in warehouses, garages, basements, parking lots, commercial buildings and residential buildings, to accept water or other liquids from the top surface of the floor and provide a means for such liquids to flow into an underlying drain pipe. The drain is typically funnel shaped, with a tapered upper portion or drain head and a lower stem adapted for connecting the drain to an adaptor or extension member for a drain pipe projecting from the ground or substrate underlying the slab. The drain head includes a grate or strainer at an upper end thereof to prevent large pieces of debris from entering and clogging the drain pipe.
A typical prior art installation assembly includes a female threaded adaptor or connector that is attached to a vertically extending drain pipe. A drain, drain assembly or cleanout with a threaded lower section is threaded into the adaptor. As used herein, the term drain is intended to be interpreted broad enough to include cleanouts or cleanout cover assemblies as well as drains or drain assemblies. The height of the drain or drain assembly may be minimally adjusted up or down by threading the drain further into or out of the adaptor.
Typically, drain adaptors and associated drains are installed upon the drain pipe prior to pouring the surrounding concrete slab that typically provides the primary floor support surface. Ideally, the drain is installed by the plumber at the proper height to allow for proper drainage and so that the grate will be flush with the finished floor surface. Plumbers will often cover the drains with duct tape or plastic to prevent the heads of the drains or drain heads from being damaged or infiltrated by concrete during pouring of the floor. Considerable time is then required to clean the drains, to remove tape or the like after the floor has been poured and set. In addition, the drains are subject to damage from heavy loads rolled across the floor during construction of additional building structures.
Additional problems can arise when a layer of tile or other flooring material is installed over the concrete slab. In such instances, the plumber typically installs the drains so that the top surfaces will extend above the level of the slab a distance equal to the thickness of the flooring. Unfortunately, it is not uncommon for concrete crews to mistakenly pour the slab to the top of the drains instead of the specified lower level, thereby creating the need for further upward adjustment of the drains. Such adjustment is often not provided for by the drain and adaptor assembly. Alternatively, concrete crews sometimes take it upon themselves to lower the drains to the level of the concrete pour.
In either case, once the concrete is poured around the drains and has set, it is usually impossible to raise or lower the drains (accomplished by turning them relative to the associated adaptor) without chipping away the concrete surrounding the drain to provide clearance for lugs usually formed on the bottom of the drain head and to break the adhesion between the concrete and the drain head surface. Similarly, if the building owner later decides to add a layer of flooring over the slab or to substitute existing flooring with a thicker layer, it is usually impossible to raise the drains to the higher level without first chipping or breaking away the concrete from around the drain head.
It is clear that there is an existing need for a system for installing floor drains that provides for easy installation, reduces damage to drain heads during and after pouring the surrounding slab, and provides a ready means for later height adjustment.